<template>
    <div class="upload-file">
        <el-upload
                multiple
                :action="uploadFileUrl"
                :before-upload="handleBeforeUpload"
                :file-list="fileList"
                :limit="limit"
                :on-error="handleUploadError"
                :on-exceed="handleExceed"
                :on-success="handleUploadSuccess"
                :show-file-list="false"
                :headers="headers"
                class="upload-file-uploader"
                ref="fileUpload"
        >
            <!-- 上传按钮 -->
            <el-button type="primary">选取文件</el-button>
        </el-upload>
        <!-- 上传提示 -->
        <div class="el-upload__tip" v-if="showTip">
            请上传
            <template v-if="fileSize"> 大小不超过
                <b style="color: #f56c6c">{{ fileSize }}MB</b>
            </template>
            <template v-if="fileType"> 格式为
                <b style="color: #f56c6c">{{ fileType.join("/") }}</b>
            </template>
            的文件
        </div>
        <!-- 文件列表 -->
        <transition-group class="upload-file-list el-upload-list el-upload-list--text" name="el-fade-in-linear"
                          tag="ul">
            <li :key="file.uid" class="el-upload-list__item ele-upload-list__item-content"
                v-for="(file, index) in fileList">
                <el-link :href="`${file.url}`" :underline="false" target="_blank">
                    <span class="el-icon-document"> {{ getFileName(file.name) }} </span>
                </el-link>
                <div class="ele-upload-list__item-content-action">
                    <el-link :underline="false" @click="handleDelete(index)" type="danger">删除</el-link>
                </div>
            </li>
        </transition-group>
    </div>
</template>

<script setup>
import {listByIds, delOss} from "@/api/system/oss";

const props = defineProps({
    modelValue: [String, Object, Array],
    // 数量限制
    limit: {
        type: Number,
        default: 5,
    },
    // 大小限制(MB)
    fileSize: {
        type: Number,
        default: 5,
    },
    // 文件类型, 例如['png', 'jpg', 'jpeg']
    fileType: {
        type: Array,
        default: () => ["doc", "xls", "ppt", "txt", "pdf"],
    },
    // 是否显示提示
    isShowTip: {
        type: Boolean,
        default: true
    }
});


const emit = defineEmits(['update:modelValue', 'over']);
const { msgSuccess, msgError, closeLoading, loading} = useModal()

const fileUpload = ref()

const number = ref(0);
const uploadList = ref([]);
const baseUrl = import.meta.env.VITE_APP_BASE_API;
const uploadFileUrl = ref(baseUrl + "/system/oss/upload"); // 上传文件服务器地址
const headers = ref({Authorization: "Bearer " + getToken()});
const fileList = ref([]);
const showTip = computed(
        () => props.isShowTip && (props.fileType || props.fileSize)
);

watch(() => props.modelValue, async val => {
    if (val) {
        let temp = 1;
        // 首先将值转为数组
        let list;
        if (Array.isArray(val)) {
            list = val;
        } else {
            await listByIds(val).then(res => {
                list = res.data.map(oss => {
                    oss = {name: oss.originalName, url: oss.url, ossId: oss.ossId};
                    return oss;
                });
            })
        }
        // 然后将数组转为对象数组
        fileList.value = list.map(item => {
            item = {name: item.name, url: item.url, ossId: item.ossId};
            item.uid = item.uid || new Date().getTime() + temp++;
            return item;
        });
    } else {
        fileList.value = [];
        return [];
    }
}, {deep: true, immediate: true});

// 上传前校检格式和大小
function handleBeforeUpload(file) {
    // 校检文件类型
    if (props.fileType.length) {
        const fileName = file.name.split('.');
        const fileExt = fileName[fileName.length - 1];
        const isTypeOk = props.fileType.indexOf(fileExt) >= 0;
        if (!isTypeOk) {
            msgError(`文件格式不正确, 请上传${props.fileType.join("/")}格式文件!`);
            return false;
        }
    }
    // 校检文件大小
    if (props.fileSize) {
        const isLt = file.size / 1024 / 1024 < props.fileSize;
        if (!isLt) {
            msgError(`上传文件大小不能超过 ${props.fileSize} MB!`);
            return false;
        }
    }
    loading("正在上传文件，请稍候...");
    number.value++;
    return true;
}

// 文件个数超出
function handleExceed() {
    msgError(`上传文件数量不能超过 ${props.limit} 个!`);
}

// 上传失败
function handleUploadError(err) {
    msgError("上传文件失败");
}

// 上传成功回调
function handleUploadSuccess(res, file) {
    if (res.code === 200) {
        uploadList.value.push({name: res.data.fileName, url: res.data.url, ossId: res.data.ossId});
        uploadedSuccessfully();
    } else {
        number.value--;
        closeLoading();
        msgError(res.msg);
        fileUpload.value.handleRemove(file);
        uploadedSuccessfully();
    }
}

// 删除文件
function handleDelete(index) {
    let ossId = fileList.value[index].ossId;
    delOss(ossId);
    fileList.value.splice(index, 1);
    emit("update:modelValue", listToString(fileList.value));
}

// 上传结束处理
function uploadedSuccessfully() {
    if (number.value > 0 && uploadList.value.length === number.value) {
        fileList.value = fileList.value.filter(f => f.url !== undefined).concat(uploadList.value);
        uploadList.value = [];
        number.value = 0;
        closeLoading();
        emit("update:modelValue", listToString(fileList.value));
        emit('over', 'success')
        msgSuccess("上传成功")
    }
}

// 获取文件名称
function getFileName(name) {
    // 如果是url那么取最后的名字 如果不是直接返回
    if (name.lastIndexOf("/") > -1) {
        return name.slice(name.lastIndexOf("/") + 1);
    } else {
        return name;
    }
}

// 对象转成指定字符串分隔
function listToString(list, separator) {
    let strs = "";
    separator = separator || ",";
    for (let i in list) {
        if (list[i].ossId) {
            strs += list[i].ossId + separator;
        }
    }
    return strs !== "" ? strs.slice(0, strs.length - 1) : "";
}
</script>

<style scoped lang="scss">
.upload-file-uploader {
    margin-bottom: 5px;
}

.upload-file-list .el-upload-list__item {
    border: 1px solid #e4e7ed;
    line-height: 2;
    margin-bottom: 10px;
    position: relative;
}

.upload-file-list .ele-upload-list__item-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    color: inherit;
}

.ele-upload-list__item-content-action .el-link {
    margin-right: 10px;
}
</style>
